Serous borderline tumor of the paratestis: a report of seven cases

Our plain-English summary of Serous borderline tumor of the paratestis: a report of seven cases, by R.F. McClure, G.L. Keeney, T.J. Sebo, et al (The American Journal of Surgical Pathology, 2001).

The study

• Authors: R.F. McClure, G.L. Keeney, T.J. Sebo, J.C. Cheville
• Journal: The American Journal of Surgical Pathology
• Published: 2001;25(3):373-8
• Cited by: 59 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

We report the clinical, morphologic, immunophenotypic, and ploidy findings of seven cases of serous borderline tumor of the paratestis. Mean patient age was 56 years (range, 14-77 years), and the clinical presentation was that of a testicular mass. Tumors ranged in size from 1 to 6 cm (mean, 3.5 cm). Six tumors arose from the tunica albuginea, and two of these tumors were intratesticular. One tumor arose from the tunica vaginalis. Serous borderline tumor of the paratestis is histologically identical to its ovarian counterpart. The tumors were cystic with numerous intracystic blunt papillae lined by stratified epithelial cells with minimal to mild cytologic atypia. Psammoma bodies were present in two cases. In all cases, the neoplastic cells stained strongly and diffusely for cytokeratin 7, estrogen receptor, and CD15, and six of seven cases were positive for progesterone receptor and MOC-31. The cells did not stain for cytokeratin 20, carcinoembryonic antigen, calretinin, and HER2/neu. Proliferative activity, as assessed by MIB-1 staining, ranged from 1.3% to 10% (mean, 5.5%). Five of six tumors were diploid, and one was tetraploid. Patients were treated by radical orchiectomy and followed up from 4 months to 18 years (mean, 48 months; median, 8.5 months). No recurrences or metastases occurred. Serous borderline tumor of the paratestis is morphologically and immunophenotypically identical to ovarian serous borderline tumor. To date, no serous borderline tumor of the paratestis reported in the literature or in our series has recurred or metastasized after resection.

In plain English

This was a case series from the Mayo Clinic in Rochester, Minnesota. The authors searched the clinic's slide files from 1909 to 1999 and described seven patients with serous borderline tumor of the paratestis, a rare growth in the tissue around the testicle that resembles a type of ovarian tumor. The article does not discuss asbestos or any other exposure. Patients were aged 14 to 77 years (mean 56). All had a painless testicular mass and had the testicle removed (radical orchiectomy). Six tumors arose from the tunica albuginea and one from the tunica vaginalis. Under the microscope and with special stains, the tumors looked like ovarian serous borderline tumors. None stained for calretinin, while the comparison cases of adenomatoid tumor and malignant mesothelioma did. Mean MIB-1 growth activity was 5.5% in the borderline tumors and 18.5% in the malignant mesotheliomas. Six patients had follow-up, lasting 4 months to 18 years, and all were tumor-free. The authors concluded that the data suggest these tumors behave in a benign manner, but said longer follow-up of more cases is needed.

We wrote this plain-English summary from the full article with the help of AI, and a second AI model checked each sentence against the article. It is not the authors' wording; the abstract and the article are their own account.

What the study did and found

• Design: Case series (clinicopathologic study of seven cases) with staining, DNA ploidy and MIB-1 analyses, plus comparison with other paratesticular tumors and a summary of 11 previously reported cases
• Who was studied: Seven patients with paratesticular serous borderline tumor from the Mayo Clinic slide files, 1909 to 1999, aged 14 to 77 years. Comparison cases were 1 serous carcinoma, 2 papillary cystadenomas of the epididymis, 5 adenomatoid tumors and 3 malignant mesotheliomas of the paratesticular region.
• Main results:
  • Patients with serous borderline tumor ranged in age from 14 to 77 years (mean 56, median 65).
  • All seven patients had a painless testicular mass and were treated by radical orchiectomy.
  • Six of seven tumors arose from the tunica albuginea (two of them within the testicle) and one arose from the tunica vaginalis.
  • None of the serous borderline tumors stained for cytokeratin 20, CEA, calretinin or HER-2/neu. All stained strongly for CK7, ER and CD15.
  • MIB-1 proliferative activity in the serous borderline tumors ranged from 1.3% to 10% (mean 5.5%).
  • In the comparison cases, adenomatoid tumors and malignant mesothelioma stained positive for calretinin and cytokeratin and negative for MOC-31, CD15 and CEA. Malignant mesotheliomas had a higher mean MIB-1 activity (18.5%) than adenomatoid tumors and serous borderline tumors.
  • Follow-up was available for six of seven patients and ranged from 4 months to 18 years. One patient died of myocardial infarction 10 months after surgery and was tumor-free. The rest were alive and free of tumor.
• The authors' conclusion: The authors concluded that paratesticular serous borderline tumors are histologically and immunophenotypically identical to ovarian serous borderline tumors, and that the data suggest they behave in a benign manner, although longer follow-up of more cases is needed.
• Limitations the authors state:
  • Follow-up time was limited, in this study and in many earlier reports.
  • The patient with the tetraploid tumor was lost to follow-up.

Topics

Medical terms in this study, explained in our Lexicon: Tunica Vaginalis, Papillae, MOC-31, Carcinoembryonic Antigen (CEA), Calretinin, HER2, Orchiectomy.

Related studies

• Cytopathology of serous neoplasia of the ovary and the peritoneum: differential diagnosis from mesothelial proliferations — L.R. Pisharodi, C.W. Bedrossian (1996)
• Evaluation of MTAP immunohistochemistry loss of expression in ovarian serous borderline tumors as a potential marker for prognosis and progression — N. Nilforoushan, N.A. Moatamed (2020)
• Immunohistochemical profile of paratesticular serous papillary adenocarcinoma and tunica vaginalis facilitates distinction from malignant mesothelioma — P.R. Anchala, R. Dhir, et al. (2011)
• Are all adenomatoid tumors adenomatoid mesotheliomas? — C.L. Davy, C.K. Tang (1981)
• Papillary serous carcinoma of the tunica vaginalis testis — P. Becerra, M.A. Isaac, et al. (2000)
• Malignant peritoneal mesothelioma in a woman with bilateral ovarian serous borderline tumour: Potential interactions between the two diseases — L. Losi, L. Botticelli, et al. (2018)

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